use core::arch::x86_64::_rdrand64_step;
use getrandom::register_custom_getrandom;

fn rdrand_getrandom(buf: &mut [u8]) -> Result<(), getrandom::Error> {
    buf.chunks_mut(8).try_for_each(|chunk| {
        let mut val: u64 = 0;
        let ok = (0..10u8).any(|_| unsafe { _rdrand64_step(&mut val) } == 1);
        match ok {
            true => {
                chunk.copy_from_slice(&val.to_ne_bytes()[..chunk.len()]);
                Ok(())
            }
            false => Err(getrandom::Error::UNSUPPORTED),
        }
    })
}

register_custom_getrandom!(rdrand_getrandom);